This invention relates to a lamp assembly and, particularly but not exclusively, to an assembly of ultra violet lamps for curing ink on printed web material and which can be incorporated in a printing press.
In a conventional printing press, ink (or other coating material) which has been deposited on a substrate is dried by the application of heat. Relatively recently, some printing presses have been using coating material which is cured by ultra violet light and this offers the attraction that curing can be effected in a fraction of a second, so leading to increased productivity and saving in space.
An ultra violet lamp of relatively short length is capable of producing a high radiant flux density and such a lamp can be restarted rapidly. As the length of the lamp is increased, there is a reduction in the radiant flux density that can be produced and an increase in the restart time. There is presently a requirement for an ultra violet light source which is capable of curing ink printed on relatively wide web material. The use of a relatively long ultra violet lamp as the ultra violet light source is not satisfactory as such a lamp would produce a relatively low radiant flux density and have a relatively long restart time. There is also a requirement to be able to remove and replace lamps easily and quickly.